Smith was backed by 90 Labour parliamentarians, according to the BBC. This was 25 more votes than former shadow business secretary Angela Eagle received, who dropped out of the leadership race shortly after.

This means that the Labour rebels' hopes of replacing Corbyn with a more moderate leader now totally rest on Smith — who has claimed in numerous times, including in an ITV interview, that he had no intention of standing a couple of weeks ago.

The result of the election will be announced on September 24, meaning Smith has just over two months to persuade the Labour membership that he is the man to lead the party into the 2020 election.

This is everything we know so far about Owen Smith.

Who is he?

Smith was born in Lancashire and raised in south Wales.

He attended a state school before studying French and History at the University of Sussex.

Smith has been the MP for Pontypridd since 2010 — meaning he does not boast years of experience as a parliamentarian.

He resigned as shadow work and pensions secretary last month as part of the party revolt against Jeremy Corbyn.

Prior to pursuing a career in politics, Smith was a producer for BBC Wales and lobbyist for pharmaceutical company Pfizer.

What does he stand for?

Smith describes himself as being "on the left of Labour" — somewhere between Eagle's centrism and the Corbyn's hard socialism. It is for this reason that some believe he may be able to win over some Corbyn supporters.

He told Channel 4 last week that he shares many of Corbyn's values but criticised the under-pressure leader for not knowing what he stands for. "It is not enough just to be anti-austerity, you have got to be pro-something and I am pro-prosperity," he said.

Smith was not an MP when parliament voted on the Iraq invasion in 2003, but he told Channel 4 that if had been he would have voted against intervention.

However, people have pointed out that in a 2006 interview with Wales Online, he was more positive about the invasion. He said: "I thought at the time the tradition of the Labour Party and the tradition of left-wing engagement to remove dictators was a noble, valuable tradition, and one that in South Wales, from the Spanish Civil War onwards, we have recognised and played a part in."

As shadow work and pensions secretary, he strongly opposed the government's planned cuts to tax credits and disability benefits. In March this year, he asked former government minister Iain Duncan Smith "how he sleeps at night" in reference to planned cuts to disability support.

His critics point to the fact that he abstained in a Commons vote on the government's contentious welfare bill last year. He has since described the decision as a "mistake."